The human race is living beyond its means. A report backed by 1,360 scientists from 95 countries - some of them world leaders in their fields - today warns that the almost two-thirds of the natural machinery that supports life on Earth is being degraded by human pressure. The study contains what its authors call "a stark warning" for the entire world. The wetlands, forests, savannahs, estuaries, coastal fisheries and other habitats that recycle air, water and nutrients for all living creatures are being irretrievably damaged. In effect, one species is now a hazard to the other 10 million or so on the planet, and to itself."Human activity is putting such a strain on the natural functions of Earth that the ability of the planet's ecosystems to sustain future generations can no longer be taken for granted," it says. The report, prepared in Washington under the supervision of a board chaired by Robert Watson, the British-born chief scientist at the World Bank and a former scientific adviser to the White House, will be launched today at the Royal Society in London. It warns that:
· Because of human demand for food, fresh water, timber, fibre and fuel, more land has been claimed for agriculture in the last 60 years than in the 18th and 19th centuries combined.*snip*
· An estimated 24% of the Earth's land surface is now cultivated.
· Water withdrawals from lakes and rivers has doubled in the last 40 years. Humans now use between 40% and 50% of all available freshwater running off the land.
· At least a quarter of all fish stocks are overharvested. In some areas, the catch is now less than a hundredth of that before industrial fishing.
· Since 1980, about 35% of mangroves have been lost, 20% of the world's coral reefs have been destroyed and another 20% badly degraded.
· Deforestation and other changes could increase the risks of malaria and cholera, and open the way for new and so far unknown disease to emerge.